Toy building block



FIG. 1 is a top perspective view of a toy building block showing my newdesign;

FIG. 2 is a bottom perspective view;

FIG. 3 is a top plan view;

FIG. 4 is a bottom plan view;

FIG. 5 is a side elevational view;

FIG. 6 is a front elevational view; and

FIG. 7 is a rear elevational view thereof.

The ornamental design for a toy building block, substantially as shownand described.